Understanding the genetic history of diseases like plague and leprosy helps us develop better strategies to combat them, offering insights into how pathogens adapt and spread.
Two recent studies published in Science delve into the history of plague and leprosy by analyzing ancient bacterial DNA. Researchers at the Institut Pasteur and McMaster University investigated why plague epidemics lasted so long. They examined samples of Yersinia pestis, the bacterium causing bubonic plague, from different pandemics.
The study found that in all three major plague pandemics, the bacterium evolved to become less virulent. While seemingly counterintuitive, this reduced virulence prolonged the epidemics. Less severe infections meant the disease had more opportunities to spread from person to person.
In a separate study, researchers from the Institut Pasteur and the University of Colorado examined leprosy in the Americas. They analyzed ancient DNA samples and discovered Mycobacterium lepromatosis, a bacterium involved in leprosy, dating back 9,000 years. This finding suggests that leprosy was present in the Americas long before European colonization.
While Europeans introduced another leprosy-causing bacterium, Mycobacterium leprae, the discovery highlights the need to study Mycobacterium lepromatosis further. Understanding the evolution and spread of these diseases provides valuable insights for developing effective prevention and treatment strategies. This knowledge helps us better prepare for and combat future outbreaks.
By studying ancient DNA, scientists gain a deeper understanding of how pathogens adapt and spread, leading to better strategies for disease control and prevention. This research underscores the importance of studying the past to protect our future.